1. Field of the Invention
The present invention relates to a coaxial tube holder, more particularly to a coaxial tube holder by which the installation can be finished very easily and securely between the head tube and the fork tube of bicycle, and the overall design is made to be more novel and dazzling so as to attract more consumer groups to purchase by providing decorative body such as patterns, veins on an ornamental cover, and hence substantial benefit of enhancing competitiveness of industry is achieved.
2. Brief Description of Prior Art
In order to keep better control on bicycle riding, usually a headset is installed between the fork tube and the head tube. Referring to FIG. 5, in which a conventional headset (7) and a fork tube (8) are shown, the headset (7) comprises upper and lower cup sets (71), (72) in which the bearing seat bodies (711), (721) are respectively installed on the upper and lower ends of the head tube (9) of bicycle; then a lower cup (722) of the lower cup set (72) is assembled on the lower end of the head tube, while a cone shape grooved pad (712) is put on the upper end of the heat tube (9) before an upper cup (713) is overlaid thereon; the fork tube is in turn penetrated through the head tube (9); and then the lower cup set (72) is fixed on the lower end of the head tube (9); while on the upper cup set (71) side, the cone shape grooved pad (712) is shrunk by the pressing of an annular recess (714) so as to tighten the fork tube (8) in place. In this manner, the installation among the headset (7), the fork tube (8) and the head tube (9) are completed.
It is apparent that, from above description, the upper cup set (71) of the conventional headset (7) should be assembled with upper cup (713) by the assistance of the cone shape grooved pad (712) so as to achieve firm assembly effect. Accordingly, more components have to be used and thus overall cost and labor hour are high in assembly operation. Once the upper cup (713) and the grooved pad (712) are loosened, the effect of holding the fork tube (8) by the grooved pad (712) will disappear such that the entire assembly structure is also loosened. Furthermore, in order to render stiffness to the upper cup (713), metal material is the only choice for the upper cup (713) and the grooved pad (712), hence the overall shape looks so dull and monotonic. For consumer groups preferring novel, dazzling perception and wanting to emphasize features of individuals, groups or companies, this seems to be short of attraction.
In view of a lot of disadvantages found in the design of the upper cup set of conventional headset, the inventor of the present invention hereby proposes a coaxial tube holder of the present invention according to his research and development conducted on state-of-art improvement for the upper cup set of conventional headset based on the assistance of his abundant experience of R&D and manufacturing in relevant field and innovative thinking in many ways.